1. Field of the Present Invention
The present invention relates to a fluid machine for separating lubricant oil from a working fluid and for feeding the oil to a part requiring lubrication, a Rankine cycle using the same, and a control method for the same.
2. Description of the Related Art
A conventional fluid machine include a heat exchanger for introducing a high heat source into an oil reservoir of an oil separator via piping, in a Rankine cycle including an expansion unit, a condenser, a refrigerant pump, a steam generator, and the oil separator (as disclosed in, for example, JP-A-58-32908). The oil containing liquid refrigerant in the oil reservoir is appropriately overheated by controlling an amount of feed of the heat from the high heat source introduced into the heat exchanger. The liquid refrigerant dissolved in the oil is evaporated, so that the oily, excellent lubricant oil is fed to the expansion unit via an oil pipe.
However, the above-mentioned oil separation technique requires control of the heat exchanger and of appropriate adjustment of the feed amount from the high heat source so as to separate oil from refrigerant. This results in increased number of components constructing a fluid machine device, thereby needing a large setting space and large cost for the device.